Chip,
Which lens, of the (7) seven, separate focal lengths available, gave you the flare problem?
As mentioned, some people have had good things to say about the 55mm, others...not so much.
I consider myself fortunate...my 55mm is a great performer.
Most folks have mixed or poor feelings concerning the 250mm, too.
I also have a copy of the '180 super.' A stellar performer...and one of my favorite focal lengths for MF portraiture.
I have two versions of the 80mm. Both are black, but one is the latest, Black 'S' series...multi-coated.
Again...another good performer. My other 80mm is wholly acceptable.
When it comes to lens hoods...I hate (make that...loath), the Mamiya lens hoods.
They're too expensive, inadequate (too short), too clunky or cumbersome, and most will mar the lens barrels.
For all of my Mamiya, TLR lenses, I use step-up rings...from 46mm or 49mm...stepped-up to 52mm.
I then use inexpensive, easily sourced, 52mm, round rubber lens hoods.
Similar to this example:
http://farm1.staticflickr.com/210/470197338_9ac084e115_z.jpg
$4-$5 for each step-up ring, and another $3-$4 for each of (3) three, rubber hoods, (wide, normal, and long).
Only a very small, (mostly unnoticeable), bump-of-a-shadow, appears in the bottom of the viewfinder from this combination.
Lens flare in my lenses, (or images) has been noticeable reduced using this trick with the cheap hoods.
Also...I too, take many of Ken Rockwell's comments with a grain of salt.
Marc